This is probably a stupid question but it could reveal an American locution I don’t know.
Why is Spidey referred to in this way by Marvel Comics in a series title and why does he sign his notes:
“Your friendly neighborhood
Spider-man” (spaced that way and without a comma in the movie)
and not “Your friendly neighbor, Spider-man”?
Is “neighborhood” working as an adjective here, implying that there are other friendly neighborhood superheroes? This would be as in “Mrs Parker is our obnoxious neighborhood busybody” but you can’t say “That guy on the wall over there is our neighborhood Spider-man” because it implies other neighborhoods could have one!
Is the neighborhood or Spidey friendly or both or what? Is it just sloppy English?

It’s a play on the cliche of local businesses, shop owners, etc., referring to themselves as “your friendly neighborhood {whatever}”. Friendly neighborhood grocer, friendly neighborhood dry cleaner, friendly neighborhood mechanic, etc. Neighborhood is being used as an attributive noun, analogous to village in “village smithy” or “village idiot”.

The online OED, I find, even has an entry for this usage, with the first citation back to 1955: “W. GADDIS Recognitions II. ii. 366 Just tell Mummy to ask about Cuff next time she visits her friendly neighborhood druggist.” The OED also notes that the phrase is often used ironically: “1973 ‘R. MACLEOD’ Nest of Vultures vii. 154, I feel like I’ve just made a date with the friendly neighbourhood vampire. 1980 Maledicta Summer 6 They become acceptable even to..your friendly neighbourhood bigot. ... 2000 Ralph 7 July 60/3 Ian and his mates needed cars for robberies, ferrying the hot gear, then dropping in on their friendly neighbourhood drug dealer.”

Spider-man is a name and names can be anything. Fictional or not, I don’t think the idea of correctness applies to names. My British friends were quick to tell me that mine is a distinctly American point of view as they have a Book of Names and all suitable names are found in it. My English girlfriend remarked to me one evening that a new American girl with name of Brandi had been hired in her office. “A name suitable for a pet, not a person.”

If you need to find a distinction between Batman and Spider-man, the obvious one is that Batman does not possess the “powers” of a bat while Spider-man does possess the “powers” of a spider.